Wire-mesh filtering-screen.



A. B. MITCHELL.

WIRE MESH FILTERING SCREEN.

APPLICATION FILED FEB. 2. I9I5.

Patented Oct. 99, 1918.

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To all whom t may' concern Mba- ' ARTHUR B. MITCHELL, BIRMINGHAM,ALABAMA.

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Specification of Letters Patent.

Fatented Uct. 29, 19H8.

Application filed February 2, 1915. Serial No. 5,810.

` Beit known that l, ARTHUR B. MrroHELL, a citizen of the United Statesof America,

residing at Birmingham, in the county of Jefferson and State of Alabama,have invented certain new and useful Improvevments in Wire-MeshFiltering-Screens, 4of

vv rich-the following is a specificati-.ioni

My invention relates to a novel type of wire mesh screen which isespecially adapted for conditions of use which require a screen of a'very Yfine mesh which shalll possess substantial body strength andstiffness.

rihe particular object of my invention is to design a wire mesh screenwhich will effectively filter acetylene or other gases, having linematter'i'n suspense therein, and deliverv the gas in a substantiallypure condition to the burner or other point of use. Filtering screens ofthis type have not heretofore been successfully obtained from a, singlethickness of wire mesh havingthe requisite iineness of mesh because itwas found in such cases that the screen was not only very fleXible andflimsy, but that the meshes became readily clogged. According to myinvention l propose to form such a' screen by a pair of superimposedattached layers of different size wire mesh which are so combined andarranged that the strands of larger mesh screen when superimposed overthe strands of the smaller substantially bisect the rectangularinterstices of the latter. As a result a corresponding reinforced wirescreen is obtained having a screening or liltering capacity equivalentto a screen of double the number of meshes of the layer having thesmaller interstices and at the same time having many times the bodystrength and rigidity of a screen formed of a single layer of the samemesh. Moreover the tendency of my compound screen to become clogged ismuch less than that of a single layer screen of the same mesh.

My invention further comprises the details of construction andarrangement of parts, which in their preferred embodiment only arehereinafter more particularly described, reference being had to theaccompanying drawings which form a part of this specification, and inwhich Figure 1 is a partial vertical sectional view showing intransverse vertical cross section my screen as applied to an acetyleneminers lamp.

Fig. 2 is a plan view of the detached screen, which is intended toillustrate the manner in which the layers of the screen, illust-rated inFig. l, are attached together and which, for the sake of clearness, donot attempt to illustrate the strands of the under layer.

F 3 is an enlarged view of a screen in `which the strands of the twosuperimposed layers are illustrated; and

` Fig. 4 is a sectional view taken on the line 3-3 of Fig. 3.

Similar reference numerals refer to simil-.1r par throughout thedrawings.

Though I have illustrated my invention as in the form particularlyadapted for a wire mesh. screen for filtering acetylene gas, I desire itto be understood that it may be applied in any oth er arts where theadvantages `inherent in my construction make it desir able. The screenis shown interposed between the bottom l of the water chamber of vthelamp and thel top 2 of the generating compartment, the screen beingdetachably held between the parts when the latter have their threadedportions screwed tightly together. The bottom l is provided with anannular gas collecting groove 3 for the filtered gas which is dischargedtherefrom in any suitable manner to the burner. The wa'- ter tube lpasses down through the center of the bottom 1 and is provided with thevalve rod 5 in accordance with the general practice. It will be notedthat the screen lies flush against the bottom l of the tank and that itpresents a strong and compact device for screening the gas and that itis readily removable and interchangeable.

The screen, as illustrated in Fig. l, comprises two superimposed layersof wire gauze which are circular in shape and are joined along theirperipheral margins by a fastening means such as a strip of solder 6.These :disks are cut away at their centers to provide for the passage ofthe tube 4; and may Jthere be joined by an inner marginal strip ofsolder 7 which holds their inner central portions in fixed relationship.In Fig. 3 I show the .ftwo superimposed layers of wire gauze, the lowerlayer being formed by the rectanguvlarly crossed strands 8 and 9. Itwill be Vapparent from this figure that the size of the mesh formed bythe strands 10 and 11 is larger than that of the mesh formed by thestrands 8 and 9. The purpose of this -dierence in mesh is to provide forthe strands of the larger mesh layer to bisect the interstices betweenthe smaller mesh strands of the lower layer. The two layers may be heldin their predetermined and contiguous relationship by any suitable meansother than that shown, but in order to obtain the results contemplatedby my invention the layers must be superimposed so that they form ineffect a compound two layer screen having, by means of the reinforcingeffect of the double thicknesses, much greater body strength andrigidity than a fine mesh screen and at the same timeforming an eX-tremely line mesh filtering screen as compared with the mesh of eitherlayer. The advantage of attaching the outer and inner margins of thescreens by solder, is that by this means I form the compound reinforcedscreen as a complete article of manufacture without requiring the screenlayers to be assembled at the time of use and which also permits thescreen to be readily applied and detached at points of use. I prefer touse two layers only as I can get access to the mesh of both layers toeffectively clean the screen.

Obviously, certain substantial benets would result from thesuperimposition and attachment of two layers of screen whether ofsimilar or dissimilar mesh in which their strands were so disposedrelatively as to reduce to a substantial extent the interstitial beinglaid to diagonally bisect the intersti- 4C tial spacesv of the otherscreen, said screens having a central opening, and marginal tastemngs tosecure the edges of the screens fixed in their said position,substantially as 4 O described. Y

2. As an article of manufacture, a filtering screen for acetylene lampsformed in two circular layers of wire screen gauze of different mesh,said screens being of such relative mesh and so superimposed as to causethe strands of the smaller mesh screen to diagonally bisect theinterstitial meshes of the larger mesh screen, and a marginal binder forrigidly holding the screenlayers contiguous in their said relationshipso that the layers reinforce each other, substantially as described. Intestimony whereof I aliix my signature in presence of two witnesses.V-

ARTHUR B. MITCHELL. Vitnesses:

NoMIn 'WELsHy R. D. JOHNSTON, J r.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

` Washington, D. C. Y

